1. Field of the Invention
This invention relates to a process for treating fractions of coal liquefaction products to produce coal derived, hydrogen-rich donor fractions suitable for use as coal liquefaction process solvents.
2. Description of the Prior Art
It is known to convert raw coal to coal liquefaction products through the use of hydrogen donor solvents. It would be desirable economically to provide a process for treating selected fractions of such products whereby they would be suitable for use as hydrogen-containing coal liquefaction solvents.
In some processes, such as U.S. Pat. Nos. 3,607,718; 3,700,583; and 3,997,425, it has been suggested that various distillate fractions can be hydrotreated in order to generate the necessary hydrogen donor solvent for recycle to the coal liquefaction zone.
In other coal liquefaction processes, such as those described in U.S. Pat. Nos. 3,607,716 and 3,607,717, the recovery of theretofore unavailable fractions of coal liquefaction products has been described. The hydrotreating of these recovered fractions, obtained via the use of deashing solvents near their critical temperature, has also been described. However, the resulting hydrotreated fractions have been described only as having use as fuels.